Mechanized rotary brush cleaner for sedimentation tanks

ABSTRACT

An arrangement for cleaning algae and other debris from the various surfaces within a sedimentation tank includes one or more mechanized rotating scrubbing brushes. In contrast to conventional arrangements that use rectangular, non-mechanized brushes, the rotational brush elements of the present invention are more effective and efficient at removing a larger quantity of material from the various interior wall surfaces (e.g., baffle, weir, spillway, etc.) within the sedimentation tank.

TECHNICAL FIELD

The present invention relates to a cleaning arrangement for asedimentation tank, such as a water or wastewater treatment tank and,more particularly, to a cleaning device that utilizes a mechanizedrotary brush arrangement to effectively remove algae and other debrisfrom various surfaces of the tank.

BACKGROUND OF THE INVENTION

A typical wastewater treatment facility includes clarifiers or settlingtanks to accomplish separation of solids from liquid. The settled solidsare removed from the bottom of the tank as sludge and the clarifiedliquid above is discharged into an effluent trough or launder. Tankgeometries and configurations vary widely but are most commonly circularwith the continuous flow of influent water entering near the center ofthe tank and the discharge of clarified effluent water occurring nearthe tank periphery. Effluent troughs and launders are generally equippedwith weirs to control the flow of the clarified supernatant. In tankswhere surface scum is prevalent, scum baffle plates are often providedadjacent to the weirs and the displaced water is forced to flow under abaffle plate that blocks floating scum. Once over the weir, the waterflows in an effluent trough or launder to a discharge pipe and on to thenext unit in the treatment process. Ultimately, the clean effluent wateris disinfected and made sufficiently safe to discharge into a river orstream.

As is known in the art, the outdoor exposure of the treatment tanks indirect sunlight encourages the unwanted growth of algae. This growth ismost prevalent one the baffle, weir, spillway and clean water flowchannel areas of the treatment tank. Disadvantageously, algae growth onthese members inhibits the flow of clean water from the tank. Further,the algae can be carried in thick masses and high concentrations in theclean water being discharged from the final treatment tank. When thisoccurs, large concentrations of chlorine are required to kill the algae.Since chlorine is relatively expensive, it is preferred to prevent thebuildup of algae.

Removing the algae from the baffle, weir, spillway and clean water flowchannel has primarily been accomplished in the past by scrubbing thetank structure by hand with long-handled brushes. Since the finaltreatment tanks are usually quite large, such a cleaning process becomesconsiderably tedious and labor-intensive.

One prior art apparatus for improving algae removal is disclosed in U.S.Pat. No. 4,830,748 issued to Ford W. Hall on May 16, 1989. The Hallcleaning apparatus comprises a series of rectangular cleaning brushesthat are attached through support arms to a main frame member. The mainframe member is attached to a conventional skimmer blade. Since theskimmer blade is designed to slowly revolve, the cleaning brushes willalso move around the tank. Thus, instead of a worker manually scrubbingalgal growth surfaces with a broom, an automated set of broomsessentially moves around the surfaces of the tank. A self-propelledversion of this apparatus (for use in arrangements without a skimmerblade) is the subject of U.S. Pat. No. 4,978,447, issued to Ford W. Hallon Dec. 18, 1990. A remaining problem with both of these arrangements,however, is that the brushes are non-mechanized (i.e., a “static” brushdesign), and a significant amount of algae and other debris may build upon the brush surfaces, thus lessening the cleaning ability of thesystem. Moreover, the rectangular brush design is not considered as themost effective cleaning arrangement.

Thus, a need remains in the prior art for a mechanized arrangement foreffectively cleaning algae and other debris from water and wastewatertreatment tanks.

SUMMARY OF THE INVENTION

The need remaining in the prior art is addressed by the presentinvention, which relates to a cleaning arrangement for a sedimentationtank, such as a water or wastewater treatment tank and, moreparticularly, to a cleaning arrangement that utilizes a mechanizedrotary brush arrangement (i.e., a “dynamic brush”) to effectively removealgae and other debris from various surfaces of the tank.

In accordance with the present invention, a sedimentation tank cleaningapparatus comprises a single rotary brush or a series of rotary brushesattached to a support arm. Each brush is mechanized (either individuallyor as a group) to rotate at a speed sufficient to effectively removealgae and other debris from the various surfaces within the tankstructure. Different sizes of brushes may be used along varioussurfaces, as need be. Moreover, different rotation speeds may be usedfor different brush locations. For example, a faster rotation may beused along the baffle and weir, where a larger amount of algae anddebris will collect. More aggressive scrubbing in these areas will serveto prevent a significant amount of algae and debris from crossing thespillway into the launder area.

Other and further embodiments and advantages of the present inventionwill become apparent during the course of the following discussion andby reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the drawings, where like numerals represent like partsin several views:

FIG. 1 contains a partial, cut-away isometric view of an exemplary priorart tank cleaning apparatus;

FIG. 2 contains a partial, cut-away isometric view of an exemplaryrotary brush tank cleaning apparatus formed in accordance with thepresent invention;

FIG. 3 is a cut-away side view of the arrangement of FIG. 2;

FIG. 4 is an enlarged illustration of an exemplary motorized brush foruse in the various embodiments of the present invention;

FIG. 5 illustrates an alternative embodiment of the present invention,in a partial, cut-away isometric view; and

FIG. 6 is a cut-away side view of the arrangement of FIG. 5.

DETAILED DESCRIPTION

Prior to describing the improvements in the cleaning of water orwastewater treatment sedimentation tanks in accordance with the presentinvention, it is considered helpful to review the state-of-the-artcleaning apparatus. In particular, FIG. 1 illustrates an exemplary priorart apparatus 10, including a set of non-mechanized or “static”scrubbing brushes that are used to dislodge algae and other debris fromsurfaces within the tank. As shown, prior art apparatus 10 includes amain frame member 12 that is attached to a skimmer blade 14 by using amounting bracket 16. During operation, skimmer blade 14 slowly revolvesaround the water treatment tank (as indicated by the arrows in FIG. 1)so as to direct any floating debris into a scum trough. In this priorart arrangement, therefore, the scrubbing brushes that are attached tomain frame member 12 will revolve in a similar manner.

Water treatment tank 20 (which is nominally circular in form, with onlya portion being illustrated in FIG. 1) includes an interior baffle 22and a weir 24 that function as described above to control the dischargeof clarified water exclusive of surface scum. As shown, weir 30 iscontiguous with a spillway 26, where spillway 26 is configured toinclude a downwardly sloping outer wall 28. Ultimately, the fullytreated water will flow into outer clean water channel 30 of tank 20.

In operation of prior art apparatus 10, a first set of brushes 32 isprovided to scrub/clean baffle 22 and weir 24, including individualbrushes to clean the inner surface of baffle 22, the outer surface ofbaffle 22 and the inside surface of weir 24. A second set of brushes 34is used to clean the outer surface of weir 24 and spillway 26, includinga brush mounted in a sloping position to clean sidewall 28 of spillway26. Lastly, a third set of brushes is used to scrub clean water channel30, with separate brushes for the sidewalls and bottom surface ofchannel 30. As mentioned above, while a degree of improvement isachieved with this prior art apparatus (as compared to manual cleaningprocesses), various amounts of algae and other debris may be lodgedagainst the static brushes, resulting in ineffective cleaning.

FIGS. 2 and 3 illustrate a first embodiment of the present inventionthat provides an improvement over prior art apparatus 10 as shown inFIG. 1. In particular, apparatus 40 is formed to includemechanically-driven rotary brushes to more effectively clean the varioussurfaces within the treatment tank. For the sake of simplicity, the sametreatment tank 20 as described above is illustrated in FIG. 2, with theonly change being the replacement of prior art apparatus 10 withinventive cleaning apparatus 40 formed in accordance with the presentinvention. Referring to FIG. 2, cleaning apparatus 40 is illustrated asincluding a support assembly 42, which extends outward from the centerof the tank (not shown) toward clean water channel 30. In the particularembodiment of FIG. 2, assembly 42 includes a first support member 44 forsupporting and driving a first plurality of mechanically-driven rotarybrushes and a second support member 46 for supporting and driving asecond plurality of mechanized rotary brushes.

FIG. 4 contains an isometric view of an exemplary mechanized rotarybrush 100 that may be used in the exemplary embodiment of the presentinvention as illustrated in FIGS. 2 and 3. As shown in FIG. 4, brush 100comprises a bristle assembly 110 disposed at the termination thereof,with bristle assembly 110 configured to rotate (in this case, in acounterclockwise direction). The rotation of bristle assembly 110 iscontrolled by a motor 120 mounted directly over and attached to bristleassembly 110. Motor 120 is sized so as to provide the desired amount oftorque required to provide the rotational movement. A control signal formotor 120, as well as the electrical, pneumatic or hydraulic powernecessary to drive motor 120, are provided as inputs from a remotesource (not shown). A handle 130 may be used as a conduit and thereaftercoupled to motor 120. In some embodiments of the present invention, thespeed of motor 120 is controllable, so as to adjust the rotational speedof bristle assembly 110.

It is to be understood that the inclusion of motor 120 on brush 100 isexemplary only. Various other arrangements may be used that include theprovision of a single, centralized motor that is coupled to eachseparate bristle assembly through an interconnection, such as a pulleysystem. While more efficient in terms of the reduction of motors andpower required, the single-motor embodiment lacks the ability to modifythe rotational speed of the individual brushes. However, eitherarrangement may be used in accordance with the present invention.

With this understanding of the particular brush assembly, it is possibleto understand the operation of the present invention by reference toFIGS. 2 and 3. Referring again to FIG. 2, first support member 44 isillustrated as providing power and movement to a first plurality ofmechanically-driven rotary brushes including an inner baffle wallcleaning brush 50, an inner weir wall cleaning brush 52, an outer weirwall cleaning brush 54, and a pair of clear water channel floor cleaningbrushes 56 and 58. It is to be understood that this particulararrangement and distribution of brushes along first support member 44 isexemplary only, and that virtually any number and arrangement ofmechanized brushes may be used. In its simplest form, a singlemechanized rotary brush may be used alone or in combination with the“static” brushes of the prior art. The rotary brush or brushes can alsobe moved manually from one cleaning surface to another. Anotherembodiment of the present invention (not shown) involves an additionalautomated mechanism to move the brush or brushes from surface tosurface.

In accordance with the present invention, the necessary power andcontrol signals are fed along first support member 44 and into theindividual motors 120 of each brush assembly 100. Elements 110, 120 and130 of an exemplary brush (as discussed above in association with FIG.4), are particularly referenced in association with brush 56 in FIG. 2.It is to be understood that each individual brush in the arrangement ofFIG. 2 contains similar elements.

Second support member 46, as shown in FIG. 2, provides power andmovement to a second plurality of mechanized rotary brushes. In thisparticular embodiment, second support member 46 is shown as coupled toan outer baffle wall cleaning brush 60, a spillway cleaning brush 62, anangled spillway brush 64 and a pair of channel wall cleaning brushes 66and 68.

The cut-away side view of FIG. 3 clearly illustrates the location of thevarious individual mechanized rotary brushes with respect to the varioussurfaces in water treatment tank 20. Particularly evident in this viewis the angular placement of brush 64, so as to accommodate thedownwardly sloping face 28 of spillway 26. The utilization of the set ofbrushes 56, 58, 66 and 68 along the surfaces of clear water channel 30are considered to be more than sufficient to remove any remaining algaeand debris that collects in this outermost region. As with thearrangement and disposition of brushes along first support member 44, itis to be understood that the various brushes included along secondsupport member 46 may vary, as need be. Indeed, it is to be understoodthat various other support arrangements, using fewer or more supportarms, may be employed, as long as the entire assembly is capable ofrotational motion around the tank while providing rotational energy tothe various brushes.

Thus, in accordance with the present invention, the application ofelectrical, pneumatic or hydraulic power signals along first and secondsupport members 44, 46 energizes the individual motors associated witheach of the illustrated rotary brushes. Upon activation, the bristleassembly will rotate at a predetermined speed to provide efficientcleaning. In one embodiment, a common control/power signal is used forthe entire combination of brushes. Alternatively, different brushes maybe coupled to separate power/control leads so as to separately adjustthe rotational speed of each brush and tailor the scrubbing ability ofeach brush for its particular use (i.e., scrubbing the weir vs.scrubbing the clear water channel).

FIGS. 5 and 6 illustrate an alternative embodiment of the presentinvention that utilizes an alternative orientation of the brushes,resulting in the use of fewer brushes and requiring only a singlesupport arm. As with the embodiment discussed above, separate motorelements (or a single motor with a pulley arrangement) are used toprovide rotational motion to each brush. Referring to FIG. 5, inventivescrubbing arrangement 70 includes a single support arm 72, with aplurality of separate brushing elements disposed along support arm 72.In particular, a first brush 74 is disposed to clean the inner wall ofbaffle 22. A second brush 76 is disposed to clean both the outer wall ofbaffle 22 and the inner surface of weir 24, where the scrubbing materialof brush 76 is appropriately sized so as to contact both surfaces (seealso the cut-away side view of FIG. 6). A third brush 78 is used toclean spillway 26, with an additional brush 80 used to scrub angledsurface 28 of spillway 26. Inasmuch as brush 80 is used to clean onlyone surface, a traditional bristled brush may be used. Lastly, a finalbrush 82 is disposed within clear water channel 30 and used to clean thebottom surface, as well as the side surfaces, of the channel. Referringto FIGS. 5 and 6, brush 82 is sized such that the bottom surface ofbrush 82 will scrub the floor of channel 30, with the outer periphery ofbrush 82 used to scrub the sidewalls of channel 30. As with theembodiment of FIGS. 2 and 3, each brush in scrubbing arrangement 70 mayinclude an individual motor to impart rotational motion to the scrubbingelements. Further, the speeds may be varied (as needed) to control thedesired degree of cleaning.

While this invention has been described fully and completely withspecial emphasis upon preferred embodiments, it should be understoodthat various modifications and alterations may be made to the particularbrush and/or support mechanism and remain within the spirit and scope ofthe present invention. Since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly, all suitable modifications and equivalentsmay be resorted to, and fall within the scope of the invention.

1. An apparatus for cleaning algae and debris from a sedimentation tankincluding a revolving skimmer and a nominally circular weir, theapparatus comprising: at least one support means; at least one rotatingbrush assembly coupled to the at least one support means, the at leastone brush assembly including at least one mechanized rotating brushelement that rotates at a predetermined speed as the apparatus revolvesaround the sedimentation tank.
 2. The apparatus as defined in claim 1wherein at least one rotating brush element is disposed along theassociated rotating brush assembly so as to contact an inside surface ofthe nominally circular weir.
 3. The apparatus as defined in claim 1wherein at least one rotating brush element is disposed along theassociated rotating brush assembly so as to contact an outside surfaceof a scum baffle within the sedimentation tank.
 4. The apparatus asdefined in claim 1 wherein at least one rotating brush element isdisposed along the associated rotating brush assembly so as to contactan inside surface of a scum baffle within the sedimentation tank.
 5. Theapparatus as defined in claim 1 wherein at least one rotating brushelement is disposed along the associated rotating brush assembly so asto contact an inside spillway between the weir and a subsequent effluenttrough.
 6. The apparatus as defined in claim 1 wherein at least onerotating brush element is disposed along the associated rotating brushassembly so as to contact a wall of a effluent trough.
 7. The apparatusas defined in claim 1 wherein at least one rotating brush element isdisposed along the associated rotating brush assembly so as to contactthe bottom of the effluent trough.
 8. The apparatus as defined in claim1 wherein at least one rotating brush element is removable from theassociated rotating brush assembly so as to be moved from one cleaningsurface to another.
 9. The apparatus as defined in claim 1 wherein theapparatus further comprises at least one non-rotating brush element. 10.The apparatus as defined in claim 1 wherein the apparatus furthercomprises a mechanical device for moving at least one rotating brushelement from one location to another.
 11. The apparatus as defined inclaim 1 wherein each rotating brush element includes a rotating elementsuch that each brush element is capable of rotating at a different,predetermined speed as the apparatus revolves around the tank.
 12. Theapparatus as defined in claim 11 wherein each rotating brush elementrotates at the same speed.
 13. The apparatus as defined in claim 12wherein the speed of the plurality of rotating brush elements isadjustable.
 14. The apparatus as defined in claim 11 wherein eachseparate rotating brush element is capable of rotating at a differentspeed.
 15. The apparatus as defined in claim 14 wherein the speed ofeach separate rotating brush element is adjustable.